Washington - Federal health regulators have scolded Coca-Cola for placing inappropriate nutritional claims on its Diet Coke Plus soft drink.

The Food and Drug Administration issued a warning letter to the company, objecting to the product's labeling, which describes the drink as "Diet Coke with Vitamins and Minerals."

Regulators said the beverage does not have enough nutrients to justify using the word "plus" in its name. According to the agency, foods labeled "plus" must have at least 10 percent more nutrients than comparable products. Additionally, the FDA said it is inappropriate to add extra nutrients to "snack foods such as carbonated beverages."

In the Dec. 10 letter, the FDA calls on Coca-Cola to revise the drink's labeling and inform the agency of its plans within 15 days. The FDA posted the letter online today.

Calls placed to Atlanta-based Coca-Cola were not immediately returned.

The FDA regularly issues warning letters to companies that do not follow regulations for manufacturing and marketing. The letters are not legally binding, but the agency can take companies to court if they are ignored.

Shares of Coca-Cola rose 16 cents to $44.83 in morning trading.